1. Field of the Invention
The present invention is in the field of spacecraft aerospace vehicle systems, and in particular relates to a launching system from an airborne platform.
2. Description of the Prior Art
Airborne aerospace vehicle operations have a number of advantages over traditional ground-based launches. A much larger first stage booster with a concomitant increase in launch costs is necessitated by ground launches. An aircraft launch provides approximately 3,000 feet per second of equivalent velocity to orbit or about 10% of the total orbital delta-V requirement. The airborne launch point can readily be selected based on orbit and safety considerations.
Previous airborne launch concepts have used either under-wing or under-fuselage attachments. These arrangements are limited by wing structural load limitations or by the available volume under the aircraft's fuselage. Other internally carried airborne concepts have relied on parachute extraction, which requires depressurizing the cabin and flying at low speed and altitude.
Pneumatic expulsion technologies have been employed for the past four decades to launch ballistic missiles from submerged submarines. The present invention incorporates similar technologies for the launch of an aerospace vehicle from an airborne platform. The specific invention is a modular airborne pneumatic launch tube system, which would independently eject an aerospace vehicle of appropriate size and mass from a military or commercial jet transport aircraft.
The "torpedo tube" aerospace vehicle launch concept provides an safe, low cost method of inserting an aerospace vehicle into an initial position of relatively high altitude (.about.35,000-40,000 feet), high subsonic Mach Number (M=0.8), and proper launch azimuth. The launch tube can accommodate multiple aerospace vehicle propulsion schemes, including solid propellants, liquid storable propellants, and cryogenic liquid propellants. Aircraft launch platforms enable open ocean launch, enhance covert operations, eliminate third party liability, and eliminate range support costs. The launch tube also serves as a means to ferry a dry (no propellant on-board) aerospace vehicle to any point on the globe prior to a mission. The modular nature of the launch tube system enables a standard military wide-body cargo jet to be utilized in two operating modes, to conduct space launch missions and to conduct routine cargo transport missions. The time estimated to retrofit to either mission is only 24 hours. No aircraft primary airframe modifications are required for this system. Only the cargo ramp door and the outer "petal" doors require modification, and they are not part of the flight structure.